Rough idling after downpipes install

[Garcia_f24]

Hey guys,

Looking for some help on this one, I've only had 2018 x5m for 4 months. I had VRSF downpipes installed a few days ago. I only noticed the rough idling a couple of days ago, so I decided to take a video.
On cold starts the car starts with no problem, but then the rpms go from 600 to 900 rpms for about a minute or two before settling at the usual 500 rpms. No error messages come up, car runs fine I haven't noticed anything wrong yet. but it never used to idle like that. any insights, help would be greatly appreciated.

Mods:
Bootmod3 stage 1
VRSF downpipes
KW V3 coilovers

Watch video below:
https://www.youtube.com/watch?v=hyxrzHvb65k

[Klienfeld303]

Originally Posted by Garcia_f24

Hey guys,

Looking for some help on this one, I've only had 2018 x5m for 4 months. I had VRSF downpipes installed a few days ago. I only noticed the rough idling a couple of days ago, so I decided to take a video.
On cold starts the car starts with no problem, but then the rpms go from 600 to 900 rpms for about a minute or two before settling at the usual 500 rpms. No error messages come up, car runs fine I haven't noticed anything wrong yet. but it never used to idle like that. any insights, help would be greatly appreciated.

Mods:
Bootmod3 stage 1
VRSF downpipes
KW V3 coilovers

Watch video below:
https://www.youtube.com/watch?v=hyxrzHvb65k

DPs require stage two BM3. Most likely why that's happening.

Did you change plugs too? Another member just posted about his stage two set up. Definitely some good info there.

[J0hnnyB0yx5m]

I have bm3 stage 2 with vrsf catless and having same issue.. had plugs changed and gapped to there spec which is 0.022-0.023 and still having same prob. I think it's the o2 sensors and I believe with bm3 they code out rears but still getting rough idle from upper getting a abnormal a/f ratio reading.. I deff wanna figure it out but haven't had time to Play with it.. good luck and deff tagging along

[GMWNashville]

Ive seen more than 1 x5/x6m have weird idle issues after downpipes. Ive talked with tuners and last I checked they didnt understand why it does it either-no issues on m5/m6. We generally dont do DP on the SUVs for this reason.

[Garcia_f24]

Just an update on this as the issue went away for me. I went from stage 1 93 octane to stage 2 93 octane, turned off Cold Start ( it was deafening in my building's garage), also turned off Catalytic Monitors ( CEL ) and that seems to have fixed my issue. on cold starts it just has one loud bang at the beginning but quickly goes down to ~650 rpms and stays there very stable.

[Djvolume]

I've been running catless for years now on my f85, same issue, resolved by turning off cold start

[X5eM]

Originally Posted by Garcia_f24

Just an update on this as the issue went away for me. I went from stage 1 93 octane to stage 2 93 octane, turned off Cold Start ( it was deafening in my building's garage), also turned off Catalytic Monitors ( CEL ) and that seems to have fixed my issue. on cold starts it just has one loud bang at the beginning but quickly goes down to ~650 rpms and stays there very stable.

Originally Posted by Garcia_f24

Just an update on this as the issue went away for me. I went from stage 1 93 octane to stage 2 93 octane, turned off Cold Start ( it was deafening in my building's garage), also turned off Catalytic Monitors ( CEL ) and that seems to have fixed my issue. on cold starts it just has one loud bang at the beginning but quickly goes down to ~650 rpms and stays there very stable.

Yeah I heard clearing the CEL and cold start usually does the trick. Went through the same thing.

[J0hnnyB0yx5m]

Has anyone sent a log of a cold start to bm3?